| Message ID | 3600031.yTsliOITBg@aspire.rjw.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On 7 December 2017 at 03:26, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Middle-layer code doing suspend-time optimizations for devices with > the DPM_FLAG_SMART_SUSPEND flag set (currently, the PCI bus type and > the ACPI PM domain) needs to make the core skip ->thaw_early and > ->thaw callbacks for those devices in some cases and it sets the > power.direct_complete flag for them for this purpose. > > However, it turns out that setting power.direct_complete outside of > the PM core is a bad idea as it triggers an excessive invocation of > pm_runtime_enable() in device_resume(). Do we need to clarify the comment about the flag in pm.h? Or is "/* Owned by the PM core */" sufficient? > > For this reason, provide a helper to clear power.is_late_suspended > and power.is_suspended to be invoked by the middle-layer code in > question instead of setting power.direct_complete and make that code > call the new helper. > > Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account) > Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account) > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro,org> Kind regards Uffe > --- > drivers/acpi/device_pm.c | 2 +- > drivers/base/power/main.c | 15 +++++++++++++++ > drivers/pci/pci-driver.c | 2 +- > include/linux/pm.h | 1 + > 4 files changed, 18 insertions(+), 2 deletions(-) > > Index: linux-pm/include/linux/pm.h > =================================================================== > --- linux-pm.orig/include/linux/pm.h > +++ linux-pm/include/linux/pm.h > @@ -765,6 +765,7 @@ extern int pm_generic_poweroff_late(stru > extern int pm_generic_poweroff(struct device *dev); > extern void pm_generic_complete(struct device *dev); > > +extern void dev_pm_skip_next_resume_phases(struct device *dev); > extern bool dev_pm_smart_suspend_and_suspended(struct device *dev); > > #else /* !CONFIG_PM_SLEEP */ > Index: linux-pm/drivers/base/power/main.c > =================================================================== > --- linux-pm.orig/drivers/base/power/main.c > +++ linux-pm/drivers/base/power/main.c > @@ -526,6 +526,21 @@ static void dpm_watchdog_clear(struct dp > /*------------------------- Resume routines -------------------------*/ > > /** > + * dev_pm_skip_next_resume_phases - Skip next system resume phases for device. > + * @dev: Target device. > + * > + * Make the core skip the "early resume" and "resume" phases for @dev. > + * > + * This function can be called by middle-layer code during the "noirq" phase of > + * system resume if necessary, but not by device drivers. > + */ > +void dev_pm_skip_next_resume_phases(struct device *dev) > +{ > + dev->power.is_late_suspended = false; > + dev->power.is_suspended = false; > +} > + > +/** > * device_resume_noirq - Execute a "noirq resume" callback for given device. > * @dev: Device to handle. > * @state: PM transition of the system being carried out. > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -999,7 +999,7 @@ static int pci_pm_thaw_noirq(struct devi > * the subsequent "thaw" callbacks for the device. > */ > if (dev_pm_smart_suspend_and_suspended(dev)) { > - dev->power.direct_complete = true; > + dev_pm_skip_next_resume_phases(dev); > return 0; > } > > Index: linux-pm/drivers/acpi/device_pm.c > =================================================================== > --- linux-pm.orig/drivers/acpi/device_pm.c > +++ linux-pm/drivers/acpi/device_pm.c > @@ -1138,7 +1138,7 @@ int acpi_subsys_thaw_noirq(struct device > * skip all of the subsequent "thaw" callbacks for the device. > */ > if (dev_pm_smart_suspend_and_suspended(dev)) { > - dev->power.direct_complete = true; > + dev_pm_skip_next_resume_phases(dev); > return 0; > } > >
On Thu, Dec 7, 2017 at 8:44 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote: > On 7 December 2017 at 03:26, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: >> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >> >> Middle-layer code doing suspend-time optimizations for devices with >> the DPM_FLAG_SMART_SUSPEND flag set (currently, the PCI bus type and >> the ACPI PM domain) needs to make the core skip ->thaw_early and >> ->thaw callbacks for those devices in some cases and it sets the >> power.direct_complete flag for them for this purpose. >> >> However, it turns out that setting power.direct_complete outside of >> the PM core is a bad idea as it triggers an excessive invocation of >> pm_runtime_enable() in device_resume(). > > Do we need to clarify the comment about the flag in pm.h? > > Or is "/* Owned by the PM core */" sufficient? That should be sufficient (and I sort of tried to ignore it ...). >> >> For this reason, provide a helper to clear power.is_late_suspended >> and power.is_suspended to be invoked by the middle-layer code in >> question instead of setting power.direct_complete and make that code >> call the new helper. >> >> Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account) >> Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account) >> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Reviewed-by: Ulf Hansson <ulf.hansson@linaro,org> Thanks!
On Thu, Dec 07, 2017 at 03:26:14AM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Middle-layer code doing suspend-time optimizations for devices with > the DPM_FLAG_SMART_SUSPEND flag set (currently, the PCI bus type and > the ACPI PM domain) needs to make the core skip ->thaw_early and > ->thaw callbacks for those devices in some cases and it sets the > power.direct_complete flag for them for this purpose. > > However, it turns out that setting power.direct_complete outside of > the PM core is a bad idea as it triggers an excessive invocation of > pm_runtime_enable() in device_resume(). > > For this reason, provide a helper to clear power.is_late_suspended > and power.is_suspended to be invoked by the middle-layer code in > question instead of setting power.direct_complete and make that code > call the new helper. > > Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account) > Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account) > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> I don't pretend to understand this (and I don't need to, so don't waste your time explaining), but I trust you :) > --- > drivers/acpi/device_pm.c | 2 +- > drivers/base/power/main.c | 15 +++++++++++++++ > drivers/pci/pci-driver.c | 2 +- > include/linux/pm.h | 1 + > 4 files changed, 18 insertions(+), 2 deletions(-) > > Index: linux-pm/include/linux/pm.h > =================================================================== > --- linux-pm.orig/include/linux/pm.h > +++ linux-pm/include/linux/pm.h > @@ -765,6 +765,7 @@ extern int pm_generic_poweroff_late(stru > extern int pm_generic_poweroff(struct device *dev); > extern void pm_generic_complete(struct device *dev); > > +extern void dev_pm_skip_next_resume_phases(struct device *dev); > extern bool dev_pm_smart_suspend_and_suspended(struct device *dev); > > #else /* !CONFIG_PM_SLEEP */ > Index: linux-pm/drivers/base/power/main.c > =================================================================== > --- linux-pm.orig/drivers/base/power/main.c > +++ linux-pm/drivers/base/power/main.c > @@ -526,6 +526,21 @@ static void dpm_watchdog_clear(struct dp > /*------------------------- Resume routines -------------------------*/ > > /** > + * dev_pm_skip_next_resume_phases - Skip next system resume phases for device. > + * @dev: Target device. > + * > + * Make the core skip the "early resume" and "resume" phases for @dev. > + * > + * This function can be called by middle-layer code during the "noirq" phase of > + * system resume if necessary, but not by device drivers. > + */ > +void dev_pm_skip_next_resume_phases(struct device *dev) > +{ > + dev->power.is_late_suspended = false; > + dev->power.is_suspended = false; > +} > + > +/** > * device_resume_noirq - Execute a "noirq resume" callback for given device. > * @dev: Device to handle. > * @state: PM transition of the system being carried out. > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -999,7 +999,7 @@ static int pci_pm_thaw_noirq(struct devi > * the subsequent "thaw" callbacks for the device. > */ > if (dev_pm_smart_suspend_and_suspended(dev)) { > - dev->power.direct_complete = true; > + dev_pm_skip_next_resume_phases(dev); > return 0; > } > > Index: linux-pm/drivers/acpi/device_pm.c > =================================================================== > --- linux-pm.orig/drivers/acpi/device_pm.c > +++ linux-pm/drivers/acpi/device_pm.c > @@ -1138,7 +1138,7 @@ int acpi_subsys_thaw_noirq(struct device > * skip all of the subsequent "thaw" callbacks for the device. > */ > if (dev_pm_smart_suspend_and_suspended(dev)) { > - dev->power.direct_complete = true; > + dev_pm_skip_next_resume_phases(dev); > return 0; > } > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Dec 8, 2017 at 9:25 PM, Bjorn Helgaas <helgaas@kernel.org> wrote: > On Thu, Dec 07, 2017 at 03:26:14AM +0100, Rafael J. Wysocki wrote: >> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >> >> Middle-layer code doing suspend-time optimizations for devices with >> the DPM_FLAG_SMART_SUSPEND flag set (currently, the PCI bus type and >> the ACPI PM domain) needs to make the core skip ->thaw_early and >> ->thaw callbacks for those devices in some cases and it sets the >> power.direct_complete flag for them for this purpose. >> >> However, it turns out that setting power.direct_complete outside of >> the PM core is a bad idea as it triggers an excessive invocation of >> pm_runtime_enable() in device_resume(). >> >> For this reason, provide a helper to clear power.is_late_suspended >> and power.is_suspended to be invoked by the middle-layer code in >> question instead of setting power.direct_complete and make that code >> call the new helper. >> >> Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account) >> Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account) >> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Acked-by: Bjorn Helgaas <bhelgaas@google.com> > > I don't pretend to understand this (and I don't need to, so don't > waste your time explaining), but I trust you :) Thank you! :-)
Index: linux-pm/include/linux/pm.h =================================================================== --- linux-pm.orig/include/linux/pm.h +++ linux-pm/include/linux/pm.h @@ -765,6 +765,7 @@ extern int pm_generic_poweroff_late(stru extern int pm_generic_poweroff(struct device *dev); extern void pm_generic_complete(struct device *dev); +extern void dev_pm_skip_next_resume_phases(struct device *dev); extern bool dev_pm_smart_suspend_and_suspended(struct device *dev); #else /* !CONFIG_PM_SLEEP */ Index: linux-pm/drivers/base/power/main.c =================================================================== --- linux-pm.orig/drivers/base/power/main.c +++ linux-pm/drivers/base/power/main.c @@ -526,6 +526,21 @@ static void dpm_watchdog_clear(struct dp /*------------------------- Resume routines -------------------------*/ /** + * dev_pm_skip_next_resume_phases - Skip next system resume phases for device. + * @dev: Target device. + * + * Make the core skip the "early resume" and "resume" phases for @dev. + * + * This function can be called by middle-layer code during the "noirq" phase of + * system resume if necessary, but not by device drivers. + */ +void dev_pm_skip_next_resume_phases(struct device *dev) +{ + dev->power.is_late_suspended = false; + dev->power.is_suspended = false; +} + +/** * device_resume_noirq - Execute a "noirq resume" callback for given device. * @dev: Device to handle. * @state: PM transition of the system being carried out. Index: linux-pm/drivers/pci/pci-driver.c =================================================================== --- linux-pm.orig/drivers/pci/pci-driver.c +++ linux-pm/drivers/pci/pci-driver.c @@ -999,7 +999,7 @@ static int pci_pm_thaw_noirq(struct devi * the subsequent "thaw" callbacks for the device. */ if (dev_pm_smart_suspend_and_suspended(dev)) { - dev->power.direct_complete = true; + dev_pm_skip_next_resume_phases(dev); return 0; } Index: linux-pm/drivers/acpi/device_pm.c =================================================================== --- linux-pm.orig/drivers/acpi/device_pm.c +++ linux-pm/drivers/acpi/device_pm.c @@ -1138,7 +1138,7 @@ int acpi_subsys_thaw_noirq(struct device * skip all of the subsequent "thaw" callbacks for the device. */ if (dev_pm_smart_suspend_and_suspended(dev)) { - dev->power.direct_complete = true; + dev_pm_skip_next_resume_phases(dev); return 0; }